Many conventional printing devices for printing images on paper or other printing media using colorants, such as toner or ink, execute a calibration process for maintaining uniform printing densities, and color balance. In the calibration process, the printing device forms density patches at a plurality of density levels with the colorant used for printing, measures the densities of these patches, and updates a correction table for correcting image data based on the measured densities. By executing this calibration process at appropriate times for updating the correction table and correcting image data based on the updated correction table, the printing device can maintain consistent quality in printed images, even when the performance of the printing device changes over time.
One such conventional printing device that performs this calibration process is configured to restrain toner consumption when the device is getting low on toner by either lengthening the interval between scheduled calibration processes or skipping the process entirely.